Catechol Dyes–Tyrosinase System for Colorimetric Determination and Discrimination of Dithiocarbamate Pesticides

Abstract

A convenient and straightforward method, which is based on catechol dyes and tyrosinase, for colorimetric determination and discrimination of dithiocarbamate pesticides (DTCs) has been fabricated. Three catechol dyes, including pyrocatechol violet (PV), pyrogallol red (PR), and bromopyrogallol red (BPR), were chosen as both substrates and indicators in this method. Tyrosinase can facilitate oxidation of the catechol dyes, altering color and absorbance spectra of the dyes. DTCs can alter the absorbance spectra of the catechol dyes–tyrosinase system due to their inhibitory effects on tyrosinase. As a result, the detection limit of the PV–tyrosinase system on ziram was determined to be 4.5 μg L–1. By implementing PV–tyrosinase, PR–tyrosinase, and BPR–tyrosinase, the colorimetric array successfully distinguished six DTCs (thiram, ziram, diram, ferbam, metiram, and mancozeb) at 5.0 μM using principal component analysis (PCA). The system can also determine ziram and distinguish DTCs in real samples. Furthermore, a smartphone can be used as a detector in this system to improve its real-world applications.

A novel fluorescent off–on probe based on 4-methylumbelliferone for highly sensitive determination of tyrosinase

“…Fluorescence spectra were recorded on a Shimadzu F-5301 spectrofluorometer with excitation and emission wavelengths at 335 and 450 nm, respectively. 1 H NMR and 13 C NMR spectra were collected on a BRUKER AVANCE III-400 MHz by dissolving the probe in DMSO-d 6 . The high resolution mass spectroscopy (HRMS) of the resultant fluorophore was collected on a microQ-TOF II mass spectrometer.…”

“…Compared with surface-enhanced Raman scattering, 11 colorimetry 12,13 and electrochemical methods, 14,15 fluorescence analysis strategies are valued for their high signal-to-noise ratio, real-time occurrence, good sensitivity, lack of complex instrumentation and additional biological advantages. Among the various TYR sensors developed, the fluorescence sensing platform based on carbon dots, 16–18 nanoclusters 19–21 and semiconductor quantum dots 22 requires large excitation energy, which leads to fluorescence instability.…”

Colorimetric Nanozyme Sensor Array Based on Metal Nanoparticle-Decorated CNTs for Quantification of Pesticides in Real Water and Soil Samples

“…The examination of the patterns acquired via the use of multivariate algorithms in machine-learning approaches unveils the specific identification and concentration of the substance being analyzed, enabling the concurrent detection of several substances. − Array-based sensing has been extensively utilized for quantification and the analysis of several toxic substances such as heavy metal ions, thiols, bacteria, biogenic amines, toxic gases, etc. Particularly, for pesticide quantification, plenty of array sensing elements were utilized based on the catechol dyes–tyrosinase system along with the utilization of push–pull chromophores containing reactive sites (i.e., alcohol, amine, pyridine active groups) and cucurbit[8]­uril complexes for colorimetric and fluorescent discrimination of pesticides, respectively . However, the synthesis of such dyes/receptors faces complicated synthesis along with their sensitivity to different reaction conditions, which limits their practical usage.…”

MnO@C composites derived from MOFs coated with reduced graphene oxide for simultaneous detection of catechol and hydroquinone

“…Catechol (CC) and hydroquinone (HQ) are isomers commonly found in phenols, which have extensive applications in various industries such as food production, dye manufacturing, pharmaceuticals and leather production [1,2]. During these production processes, they are inevitably released into the environment, thus jeopardizing human health [3][4][5].…”